[rv]

What other things can cause hum through speakers beyond the common group loop issues and wiring?


More specifically, I' m looking at what could be mechanically wrong or constructed poorly within an amplifier causing a slight amount of hum through a pair of subwoofers (this is not a major hum...but fairly low level). Could it be the power supply, a capacitor, etc?


A bit more background:


No wires/interconnects hooked up to the amplifier

Only Speaker Cables to the subs are used

The amp plugged directly into a dedicated circuit and outlet with nothing else in the outlet.



Thanks,


RV

 

[Bob Smith]

Try putting a shorted RCA plug into the input. Maybe the input is a high impedance and electric fields around the input are causing the hum. What kind of subwoofer is it?


Bob

 

[Bob Smith]

Another thought. Try using a piece of coaxial wire for the speaker lead, with the ground going to the black terminal. May be RF pickup from a local radio station causing the problem.


See if any light dimmers are on about half way, could be they are inducing noise into the power supply.


Is it a hum, or a buzz?? This could be an indication of the source.


Bob

 

[rv]

It's definitely a hum type problem, and as I've just discovered, get louder with the volume control. Shorting the inputs has no effect on the problem. The sub's themselves are Revel Sub 15's, power by the external LE-1 amplifier. Unfortunately, there are no dimmers either. Help!


RV

 

[rsg_1]

Rajeev,



More specifically, is it a hum or a hiss?


Try an experiment with a shielded speaker cable and with no other equipment hooked into the dedicated AC circuit except the amp in question. I know this may be difficult or impossible, but tell your dealer and try to get another LE-1 (probably unlikely) and duplicate the problem. Just out of curiosity, what kind of speaker cable and termination are you using?


Do you experience this problem with any other of the amps & speakers you have? You may want to also try another amp you have and wire it into the sub. See if you get the same results.


Good luck,


Rajiv...

 

[GBishop]

DO you have a TV on? I noticed the difference when the TV was on(much more hum). I've read recommendations that keep a TV 10 ft from an amplifier.

I encased most of the interconnects I have near a TV with flexible metal conduit normally used for AC wires. At $0.22 a ft you can't beat it.


Also most electrical handbooks recommend keeping data lines 2 inches from AC .


Good Luck